4-tert-Butyl­pyridinium triiodide–4-tert-butyl­pyridine (1/1)

He, H.; Sykes, A.G.

doi:10.1107/S1600536811001371

organic compounds

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ISSN: 2056-9890

Volume 67| Part 2| February 2011| Page o434

doi:10.1107/S1600536811001371

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4-tert-Butylpyridinium triiodide–4-tert-butylpyridine (1/1)

Hongshan He ^a ^* and Andrew G. Sykes ^b

^aCenter for Advanced Photovoltaics, Department of Electrical Engineering and Computer Science, South Dakota State University, Brookings, SD 57007, USA, and ^bDepartment of Chemistry, University of South Dakota, Vermillion, SD 57069, USA
^*Correspondence e-mail: hongshan.he@sdstate.edu

(Received 21 December 2010; accepted 10 January 2011; online 22 January 2011)

The title compound, C₉H₁₄N⁺·I₃⁻·C₉H₁₃N, consists of monoprotonated 4-tert-butylpyridinium cations and triiodide anions. The triiodide ion has near-symmetric linear geometry, with bond lengths of 2.9105 (4) Å (I—I) and a bond angle of 177.55 (3)° (I—I—I). For this room-temperature structure, the butyl group on the pyridine ring is disordered and has been treated as a rigid rotator, modeled in three separate positions with 1/3, 1/3, 1/3 occupancies. The cations assemble into dimeric forms by way of N—H⋯N hydrogen bonds.

Related literature

For applications of the 4-t-butylpyridine and iodide/triiodide system in dye-sensitized solar cells see: Campbell et al. (2004 ); Lee et al. (2010 ); Wang et al. (2005 ). For related structures, see: Fialho et al. (1996 ); Kochel (2006 ).

Experimental

Crystal data

C₉H₁₄N⁺·I₃⁻·C₉H₁₃N
M_r = 652.12
Tetragonal, P 4₂ /n
a = 11.6862 (4) Å
c = 17.1665 (13) Å
V = 2344.4 (2) Å³
Z = 4
Mo Kα radiation
μ = 4.00 mm⁻¹
T = 293 K
0.55 × 0.50 × 0.40 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2006 ) T_min = 0.217, T_max = 0.298
23722 measured reflections
2217 independent reflections
1758 reflections with I > 2σ(I)
R_int = 0.027

Refinement

R[F² > 2σ(F²)] = 0.037
wR(F²) = 0.090
S = 1.04
2217 reflections
119 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.80 e Å⁻³
Δρ_min = −0.77 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H99⋯N1ⁱ	0.90	1.76	2.655 (7)	172
Symmetry code: (i) $[-x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z]$ .

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: SHELXTL (Sheldrick, 2008), WinGX (Farrugia, 1999 ) and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811001371/sj5091sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811001371/sj5091Isup2.hkl

checkCIF report

Comment top

4 - t-Butylpyridine is usually added into an iodide/triiodide electrolyte solution to enhance the photovoltaic performance of dye-sensitized solar cells. The solution is a mixture of iodide, lithium iodide, 4 - t-butylpyridine, and guanidinium thiocyanate (Campbell et al., 2004; Lee et al., 2010). Alternatively, the electrolyte can be prepared by the reaction between 2-hydroxypropionitrile and lithium iodide (Wang et al., 2005). It was proposed that triiodide was produced during the reaction; however, no direct evidence was obtained. Reported here is the structure of the resulting compound.

In the molecule of the title compound, three iodide atoms in triiodide ion are in a linear geometry (Fig. 1). The I1—I2 bond length is 2.9105 (4)Å and the I2—I1—I2 angle is 177.55 (3)°. The triiodide bond is almost parallel to the pyridyl ring. In each asymmetric unit cell, two pairs of triiodide ions are perpendicular to each other (Fig. 2 and Fig. 3). The cations assemble into dimeric forms by way of N—H···N hydrogen bonds (Fig. 4, Table 1).

Related literature top

For applications of the 4-t-butylpyridine and iodide/triiodide system in dye-sensitized solar cells see: Campbell et al. (2004); Lee et al. (2010); Wang et al. (2005). For related structures, see: Fialho et al. (1996); Kochel (2006).

Experimental top

2-Hydroxypropionitrile (6.1 g) and lithium iodide (10 g) was added to a flask. The resulting mixture was heated to 120°C in a sealed high pressure tube for 30 minutes. When the temperature decreased to 70°C, silica powder with diameter 25 µm (1.3 g), 4 - t-butylpyridine (1.0 g), and ethanol (3 ml) were added. The mixture was stirred by a mechanical stirrer at 50°C for 30 minutes. Red crystals were obtained from the resulting mixture in one month.

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008), WinGX (Farrugia, 1999) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. The molecular structure of the title compound showing 30% probability displacement ellipsoids and the atomic numbering.
	Fig. 2. Packing diagram of the title compound, viewed down the a axis.
	Fig. 3. Packing diagram of the title compound, viewed down the c axis.
	Fig. 4. Packing diagram of the title compound showing the hydrogen bonding.

4-tert-Butylpyridinium triiodide–4-tert-butylpyridine (1/1) top

Crystal data top

C₉H₁₄N⁺·I₃⁻·C₉H₁₃N	D_x = 1.848 Mg m⁻³
M_r = 652.12	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P4₂/n	Cell parameters from 9942 reflections
Hall symbol: -P 4bc	θ = 2.4–25.6°
a = 11.6862 (4) Å	µ = 4.00 mm⁻¹
c = 17.1665 (13) Å	T = 293 K
V = 2344.4 (2) Å³	Block, red
Z = 4	0.55 × 0.50 × 0.40 mm
F(000) = 1232

Data collection top

Bruker APEXII CCD area-detector diffractometer	2217 independent reflections
Radiation source: fine-focus sealed tube	1758 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.027
ϕ and ω scans	θ_max = 25.6°, θ_min = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2006)	h = −14→14
T_min = 0.217, T_max = 0.298	k = −14→14
23722 measured reflections	l = −20→20

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.090	w = 1/[σ²(F_o²) + (0.0303P)² + 5.5874P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
2217 reflections	Δρ_max = 0.80 e Å⁻³
119 parameters	Δρ_min = −0.77 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00208 (15)

Crystal data top

C₉H₁₄N⁺·I₃⁻·C₉H₁₃N	Z = 4
M_r = 652.12	Mo Kα radiation
Tetragonal, P4₂/n	µ = 4.00 mm⁻¹
a = 11.6862 (4) Å	T = 293 K
c = 17.1665 (13) Å	0.55 × 0.50 × 0.40 mm
V = 2344.4 (2) Å³

Data collection top

Bruker APEXII CCD area-detector diffractometer	2217 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2006)	1758 reflections with I > 2σ(I)
T_min = 0.217, T_max = 0.298	R_int = 0.027
23722 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.037	1 restraint
wR(F²) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.80 e Å⁻³
2217 reflections	Δρ_min = −0.77 e Å⁻³
119 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
C1	0.0501 (4)	0.9717 (5)	0.3368 (3)	0.0641 (12)
H1	0.0502	1.0414	0.3107	0.077*
C2	0.1482 (4)	0.9081 (6)	0.3407 (3)	0.0749 (15)
H2	0.2140	0.9358	0.3169	0.090*
C3	0.0595 (5)	0.7687 (5)	0.4119 (3)	0.0694 (14)
H3	0.0625	0.6988	0.4376	0.083*
C4	−0.0414 (4)	0.8291 (4)	0.4105 (3)	0.0608 (12)
H4	−0.1055	0.8001	0.4360	0.073*
C5	−0.0485 (4)	0.9329 (4)	0.3715 (2)	0.0505 (10)
C6	−0.1613 (4)	0.9989 (4)	0.3681 (3)	0.0590 (12)
C7	−0.179 (2)	1.059 (2)	0.2943 (13)	0.099 (7)*	0.33
H7A	−0.1554	1.0099	0.2521	0.148*	0.33
H7B	−0.1338	1.1273	0.2937	0.148*	0.33
H7C	−0.2582	1.0775	0.2886	0.148*	0.33
C8	−0.2650 (16)	0.9078 (16)	0.3731 (13)	0.077 (5)*	0.33
H8A	−0.2680	0.8641	0.3258	0.116*	0.33
H8B	−0.3359	0.9479	0.3801	0.116*	0.33
H8C	−0.2526	0.8573	0.4164	0.116*	0.33
C9	−0.1911 (15)	1.0409 (17)	0.4482 (9)	0.051 (4)*	0.33
H9A	−0.1303	1.0882	0.4675	0.076*	0.33
H9B	−0.2017	0.9767	0.4823	0.076*	0.33
H9C	−0.2606	1.0847	0.4459	0.076*	0.33
C7'	−0.144 (2)	1.125 (2)	0.3487 (17)	0.118 (8)*	0.33
H7'1	−0.1136	1.1639	0.3933	0.177*	0.33
H7'2	−0.2159	1.1584	0.3344	0.177*	0.33
H7'3	−0.0912	1.1316	0.3060	0.177*	0.33
C8'	−0.230 (2)	0.953 (2)	0.3061 (13)	0.091 (7)*	0.33
H8'1	−0.3007	0.9947	0.3031	0.136*	0.33
H8'2	−0.2453	0.8739	0.3159	0.136*	0.33
H8'3	−0.1894	0.9609	0.2577	0.136*	0.33
C9'	−0.2236 (18)	0.9924 (19)	0.4480 (12)	0.085 (6)*	0.33
H9'1	−0.1681	0.9934	0.4892	0.127*	0.33
H9'2	−0.2673	0.9230	0.4507	0.127*	0.33
H9'3	−0.2739	1.0569	0.4534	0.127*	0.33
C8"	−0.2550 (14)	0.9235 (14)	0.3301 (12)	0.052 (3)*	0.33
H8"1	−0.3257	0.9653	0.3282	0.078*	0.33
H8"2	−0.2653	0.8553	0.3604	0.078*	0.33
H8"3	−0.2321	0.9033	0.2782	0.078*	0.33
C7"	−0.1486 (14)	1.1071 (15)	0.3079 (11)	0.057 (4)*	0.33
H7"1	−0.0932	1.1602	0.3280	0.085*	0.33
H7"2	−0.2212	1.1449	0.3027	0.085*	0.33
H7"3	−0.1240	1.0798	0.2579	0.085*	0.33
C9"	−0.1668 (19)	1.0791 (19)	0.4363 (13)	0.085 (7)*	0.33
H9"1	−0.0907	1.1022	0.4504	0.127*	0.33
H9"2	−0.2021	1.0410	0.4796	0.127*	0.33
H9"3	−0.2110	1.1452	0.4224	0.127*	0.33
N1	0.1527 (4)	0.8086 (4)	0.3770 (3)	0.0699 (12)
I1	0.2500	0.2500	0.38499 (3)	0.06646 (18)
I2	0.05632 (4)	0.40649 (4)	0.38862 (3)	0.1013 (2)
H99	0.220 (6)	0.772 (11)	0.381 (5)	0.09 (4)*	0.50

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.060 (3)	0.068 (3)	0.065 (3)	−0.004 (2)	0.000 (2)	0.009 (2)
C2	0.048 (3)	0.102 (4)	0.074 (4)	−0.002 (3)	0.008 (3)	−0.001 (3)
C3	0.067 (3)	0.068 (3)	0.073 (3)	0.013 (3)	−0.004 (3)	0.008 (3)
C4	0.055 (3)	0.059 (3)	0.068 (3)	0.001 (2)	0.007 (2)	0.007 (2)
C5	0.050 (2)	0.055 (3)	0.047 (2)	0.0031 (19)	−0.0037 (19)	−0.0077 (19)
C6	0.057 (3)	0.060 (3)	0.061 (3)	0.014 (2)	−0.006 (2)	−0.010 (2)
N1	0.053 (3)	0.091 (3)	0.066 (3)	0.020 (2)	−0.005 (2)	−0.011 (2)
I1	0.0663 (3)	0.0676 (3)	0.0656 (3)	0.0000 (2)	0.000	0.000
I2	0.0790 (3)	0.1007 (4)	0.1243 (4)	0.0253 (2)	−0.0064 (3)	0.0184 (3)

Geometric parameters (Å, º) top

C1—C2	1.368 (7)	C8—H8C	0.9600
C1—C5	1.375 (6)	C9—H9A	0.9600
C1—H1	0.9300	C9—H9B	0.9600
C2—N1	1.320 (7)	C9—H9C	0.9600
C2—H2	0.9300	C7'—H7'1	0.9600
C3—N1	1.327 (7)	C7'—H7'2	0.9600
C3—C4	1.374 (7)	C7'—H7'3	0.9600
C3—H3	0.9300	C8'—H8'1	0.9600
C4—C5	1.389 (6)	C8'—H8'2	0.9600
C4—H4	0.9300	C8'—H8'3	0.9600
C5—C6	1.528 (6)	C9'—H9'1	0.9600
C6—C8'	1.44 (2)	C9'—H9'2	0.9600
C6—C7	1.46 (2)	C9'—H9'3	0.9600
C6—C9"	1.50 (2)	C8"—H8"1	0.9600
C6—C9	1.500 (16)	C8"—H8"2	0.9600
C6—C7'	1.52 (3)	C8"—H8"3	0.9600
C6—C8"	1.549 (16)	C7"—H7"1	0.9600
C6—C9'	1.55 (2)	C7"—H7"2	0.9600
C6—C8	1.614 (19)	C7"—H7"3	0.9600
C6—C7"	1.641 (17)	C9"—H9"1	0.9600
C7—H7A	0.9600	C9"—H9"2	0.9600
C7—H7B	0.9600	C9"—H9"3	0.9600
C7—H7C	0.9600	N1—H99	0.90 (2)
C8—H8A	0.9600	I1—I2ⁱ	2.9105 (4)
C8—H8B	0.9600	I1—I2	2.9105 (4)

C2—C1—C5	120.2 (5)	H7A—C7—H7C	109.5
C2—C1—H1	119.9	H7B—C7—H7C	109.5
C5—C1—H1	119.9	C6—C8—H8A	109.5
N1—C2—C1	122.4 (5)	C6—C8—H8B	109.5
N1—C2—H2	118.8	H8A—C8—H8B	109.5
C1—C2—H2	118.8	C6—C8—H8C	109.5
N1—C3—C4	121.1 (5)	H8A—C8—H8C	109.5
N1—C3—H3	119.4	H8B—C8—H8C	109.5
C4—C3—H3	119.4	C6—C9—H9A	109.5
C3—C4—C5	120.5 (5)	C6—C9—H9B	109.5
C3—C4—H4	119.7	H9A—C9—H9B	109.5
C5—C4—H4	119.7	C6—C9—H9C	109.5
C1—C5—C4	116.5 (4)	H9A—C9—H9C	109.5
C1—C5—C6	122.8 (4)	H9B—C9—H9C	109.5
C4—C5—C6	120.7 (4)	C6—C7'—H7'1	109.5
C8'—C6—C9"	141.9 (13)	C6—C7'—H7'2	109.5
C7—C6—C9"	111.9 (14)	H7'1—C7'—H7'2	109.5
C8'—C6—C9	132.2 (12)	C6—C7'—H7'3	109.5
C7—C6—C9	127.3 (12)	H7'1—C7'—H7'3	109.5
C8'—C6—C7'	105.7 (14)	H7'2—C7'—H7'3	109.5
C9"—C6—C7'	64.7 (14)	C6—C8'—H8'1	109.5
C9—C6—C7'	85.2 (13)	C6—C8'—H8'2	109.5
C8'—C6—C5	108.8 (9)	H8'1—C8'—H8'2	109.5
C7—C6—C5	113.2 (10)	C6—C8'—H8'3	109.5
C9"—C6—C5	108.8 (9)	H8'1—C8'—H8'3	109.5
C9—C6—C5	109.3 (7)	H8'2—C8'—H8'3	109.5
C7'—C6—C5	112.3 (11)	C6—C9'—H9'1	109.5
C7—C6—C8"	78.9 (12)	C6—C9'—H9'2	109.5
C9"—C6—C8"	130.8 (11)	H9'1—C9'—H9'2	109.5
C9—C6—C8"	114.0 (11)	C6—C9'—H9'3	109.5
C7'—C6—C8"	123.5 (13)	H9'1—C9'—H9'3	109.5
C5—C6—C8"	109.8 (6)	H9'2—C9'—H9'3	109.5
C8'—C6—C9'	112.1 (14)	C6—C8"—H8"1	109.5
C7—C6—C9'	136.4 (12)	C6—C8"—H8"2	109.5
C7'—C6—C9'	107.7 (14)	H8"1—C8"—H8"2	109.5
C5—C6—C9'	110.2 (8)	C6—C8"—H8"3	109.5
C8"—C6—C9'	90.7 (11)	H8"1—C8"—H8"3	109.5
C7—C6—C8	104.9 (12)	H8"2—C8"—H8"3	109.5
C9"—C6—C8	109.8 (12)	C6—C7"—H7"1	109.5
C9—C6—C8	89.6 (11)	C6—C7"—H7"2	109.5
C7'—C6—C8	138.5 (13)	H7"1—C7"—H7"2	109.5
C5—C6—C8	108.2 (8)	C6—C7"—H7"3	109.5
C9'—C6—C8	64.5 (11)	H7"1—C7"—H7"3	109.5
C8'—C6—C7"	82.5 (11)	H7"2—C7"—H7"3	109.5
C9"—C6—C7"	90.8 (11)	C6—C9"—H9"1	109.5
C9—C6—C7"	110.2 (10)	C6—C9"—H9"2	109.5
C5—C6—C7"	109.6 (7)	H9"1—C9"—H9"2	109.5
C8"—C6—C7"	103.7 (10)	C6—C9"—H9"3	109.5
C9'—C6—C7"	129.5 (10)	H9"1—C9"—H9"3	109.5
C8—C6—C7"	127.6 (10)	H9"2—C9"—H9"3	109.5
C6—C7—H7A	109.5	C2—N1—C3	119.3 (4)
C6—C7—H7B	109.5	C2—N1—H99	120 (9)
H7A—C7—H7B	109.5	C3—N1—H99	121 (9)
C6—C7—H7C	109.5	I2ⁱ—I1—I2	177.55 (3)

Symmetry code: (i) −x+1/2, −y+1/2, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H99···N1ⁱⁱ	0.90	1.76	2.655 (7)	172

Symmetry code: (ii) −x+1/2, −y+3/2, z.

Experimental details

Crystal data
Chemical formula	C₉H₁₄N⁺·I₃⁻·C₉H₁₃N
M_r	652.12
Crystal system, space group	Tetragonal, P4₂/n
Temperature (K)	293
a, c (Å)	11.6862 (4), 17.1665 (13)
V (Å³)	2344.4 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	4.00
Crystal size (mm)	0.55 × 0.50 × 0.40

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2006)
T_min, T_max	0.217, 0.298
No. of measured, independent and observed [I > 2σ(I)] reflections	23722, 2217, 1758
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.609

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.037, 0.090, 1.04
No. of reflections	2217
No. of parameters	119
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.80, −0.77

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), SHELXTL (Sheldrick, 2008), WinGX (Farrugia, 1999) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H99···N1ⁱ	0.90	1.76	2.655 (7)	172

Symmetry code: (i) −x+1/2, −y+3/2, z.

Acknowledgements

This material is based upon work supported by the National Science Foundation/EPSCoR grant No. 0903804 and by the State of South Dakota.

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